MANKATO, Minn. — About 15 minutes into a light walkthrough practice on a breezy Monday morning, first-year Minnesota Vikings head coach Mike Zimmer changed the tone of his defensive teaching.

Instead of verbalizing the call for the next defensive play, only hand signals were used from the coaches on the sidelines to the players on the field. The team’s work was in preparation for playing in a loud stadium or if the players’ in-helmet earpieces fail during a game.

“No talking,” Zimmer said to the defense. “Use the hand signals and communicate.”

While small, it’s another new wrinkle for the Vikings’ defenders to get used to under Zimmer, the team’s new coach who was hired by Minnesota in January after 14 years in the NFL as a defensive coordinator from 2000 to 2013.

Nine-year league veteran and Mount Vernon native Chad Greenway said Zimmer has already made a strong influence on the Vikings. Greenway is playing for his third head coach with the Vikings and admits he’s looking forward to learning from Zimmer’s defensive expertise this year.

“I think we’re getting better with the defense,” Greenway said, following a 45-minute practice at the site of camp, Minnesota State University in Mankato, Minn. “There are a lot of new calls and new stuff, but for the most part we’re getting more comfortable as we’re getting longer in it. We’re able to add more things as we go, but it’s nice to be able to build that base.”

Greenway played live under Zimmer’s scheme for the first time Friday, the Vikings’ preseason opener that resulted in a 10-6 victory over the Oakland Raiders. The former Stickney/Mount Vernon standout played six snaps against Oakland, and he was already impressed with his new coach.

“It’s pretty impressive the way he can manage a game, especially the other night and to see it up close,” Greenway said. “He just sees so many things that, from a player’s perspective, is just amazing that he can see those things from the sidelines, and you just hope that you can take those things that he’s learned and apply them.”

Zimmer had stops as a defensive coordinator in Dallas, Atlanta and most recently spent the past six years with Cincinnati.

Zimmer is the ninth head coach in Vikings franchise history. He takes over a team that went 5-10-1 last year and finished last in the NFC North division. He joins Minnesota after leading Cincinnati’s defense to top-10 finishes in yards and points allowed in four of the past five seasons.

After evaluating the first preseason game, the new coach said he thinks his team looks the way he wants it to, both fast and smart.

“I want our guys to play fast, I want them to play physical,” he said Sunday. “I want them to play smart, and as a football coach I don’t really want to put them in a position where they’re not going to be successful.”

Defensive end Brian Robison, who’s entering his eighth year, said players need to focus on what is being taught by the current coaches, rather than thinking of what they’ve learned in the past.

He said that’s easy with Zimmer and new defensive coordinator George Edwards. Robison said the team will likely be more aggressive than what previous coach Leslie Frazier directed.

“Each person knows what every other person across the board is doing, and we do our defensive meetings with every single person in the room,” Robison said. “So we get to hear with (defensive backs) are doing and they get to hear what the D-line is doing, and I think that helps us because we know where everyone else is supposed to be and where they are, for the most part.”

Greenway, who has led the Vikings in tackles for six consecutive seasons, said training camp is the time to work out kinks and get the team into form for the season.

“You’ve got to make some mistakes and you have to learn from the mistakes to get a good two, three, four weeks into it,” he said. “The offseason we had this year certainly helped and we’ve been able to come here and really work at it.”

But the linebacking corps, like much of the defense, is expected to be a work in progress prior to the team’s regular-season opener Sept. 7 at St. Louis. The linebacking corps will still be relatively young, as the coaches work in first-round pick Anthony Barr, along with Jasper Brinkley, who is in his second stint with the team, with Greenway. That defensive unit, which was ranked second-to-last in the league for yards allowed per game last year, could have as many as six new starters this year.

That’s not a worry for Greenway, who said the unit is making a natural progression compared to previous years in being ready for the season.

“By the time the regular season is here, we really should be able to be dialed in and we’ll be in game shape and be game planning and have a good base of film,” Greenway said. “To have that is important and then you can start honing in on each opponent.”